VARIATIONS A2

x is inversely proportional to y. x=12 while y=5. Find y when x is 30.

Solution

x ⍺ k

      y

x = k

      y

12 = k

        5

k = 12 x 5

k = 60

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

k = 60, y= ?, x = 30.

x = k

      y

30 = 60

         y

y x 30 = 60  x  y   (multiply by y on both sides)

                y

30y = 60

30      30

y = 2

TRY THIS…………….

x is inversely proportional to y. x=20 while y=4. Find y when x is 40.